To avoid the confusion he is not talking buy-in, he is talking BR for the night. To make the answer obvious, what do you do when you have your max bet out and split to 4 hands and have to make a double down. Each hand is $100 so the 4 split is your night's BR, plus you may have to make double downs so 1 round could use as much as $800. You should have a integer multiple of that figure. Don't set a night's BR by win or loss goals. You should not use them except for heat reasons. Leaving a big plus count because you won a bet will really cut into your advantage and may have you playing at an overall disadvantage if your advantage is small.